Which one of the following sets of ions represents a collection of iso-electronic species ?

Options

A. `k^+, Cl^- , Mg^(2+) , Sc^(3+)`
B. `Na^+, Ca^(2+), Sc^(3+) , F^-`
C. `K^+ , Ca^(2+),Sc^(3+) , CL^-`
D. `Na^+ , Mg^(2+) , Al^(3+) , Cl^-`

Answer

C